Det var uheldigt, at min paraply gik i stykker lige før regnen begyndte.

Det var is a very common Danish way to say It was.

Here, det is a dummy subject, just like it in English expressions such as It was unfortunate or It was nice. It does not refer to a specific object.

So:

• Det var uheldigt = It was unfortunate

This structure is extremely common in Danish when giving an evaluation or comment about a whole situation.

Because the sentence describes something that happened in the past.

• var = past tense of er (is / was)
• Det er uheldigt = It is unfortunate
• Det var uheldigt = It was unfortunate

Since the umbrella broke before the rain started, the whole event is being told as a past situation.

Uheldigt means unfortunate, bad luck, or unlucky in this kind of sentence.

It comes from uheldig, which means unlucky or unfortunate.

Here it is in the neuter form:

• en uheldig situation = an unfortunate situation
• det var uheldigt = that was unfortunate

So uheldigt is not describing a person here; it is describing the situation as a whole.

In Danish, a subordinate clause is usually separated by a comma in writing.

Here:

• main clause: Det var uheldigt
• subordinate clause: at min paraply gik i stykker lige før regnen begyndte

So the comma marks the beginning of the at-clause.

This is very normal in Danish punctuation.

Here at means that, not the infinitive marker to.

So:

• Det var uheldigt, at ... = It was unfortunate that ...

Danish at can have two different jobs:

1. Subordinating conjunction = that

   • Jeg ved, at han kommer = I know that he is coming

2. Infinitive marker = to

   • Jeg vil gerne spise / at spise = to eat

In your sentence, it introduces a full subordinate clause, so it means that.

Gik i stykker is a very common Danish expression meaning broke or stopped working / got broken.

Literally, it is something like:

• gik = went
• i stykker = into pieces

But you should learn gå i stykker as a fixed expression.

Examples:

• Min telefon gik i stykker = My phone broke
• Cyklen gik i stykker = The bike broke

It is often used when something becomes damaged or stops functioning, even if it does not literally shatter into pieces.

Yes.

• gå i stykker = to break / to become broken
• ødelægge = to damage / to ruin something
• blive ødelagt = to get damaged / to be ruined

Important difference:

• Paraplyen gik i stykker focuses on the result: the umbrella broke.
• Jeg ødelagde paraplyen means I broke / ruined the umbrella and points to who caused it.
• Paraplyen blev ødelagt also means the umbrella got damaged, but sounds a bit more formal or passive.

For everyday speech, gik i stykker is often the most natural choice.

In Danish, you normally do not use the suffixed definite ending when there is already a possessive word like min, din, hans, vores, etc.

So:

• min paraply = my umbrella
• not min paraplyen

This is similar to English: you say my umbrella, not my the umbrella.

Regnen means the rain.

In Danish, weather nouns are often used in the definite form when referring to the specific rain in the situation.

So:

• lige før regnen begyndte = just before the rain started

Using regnen makes it sound like the rain that was about to come in that particular moment.

You may also see det begyndte at regne, which means it started raining. That is another very natural way to express the same idea.

Yes, absolutely. That would be very natural.

• lige før regnen begyndte = just before the rain started
• lige før det begyndte at regne = just before it started raining

Both are good Danish. The version with det begyndte at regne may feel a little more verbal and everyday, while regnen begyndte is also perfectly normal.

Før means before.

Lige før means just before.

The word lige adds the idea that the timing was very close.

Compare:

• før regnen begyndte = before the rain started
• lige før regnen begyndte = just before the rain started

So lige makes the sentence more specific and often more vivid.

Because in Danish subordinate clauses, the word order usually stays with the subject before the verb.

So:

• at min paraply gik i stykker
  = that my umbrella broke

This is standard subordinate clause order:

• at
  • subject + verb + rest

Compare with a main clause:

• Min paraply gik i stykker = My umbrella broke

In this case, the order looks the same, but Danish subordinate clauses become especially important when adverbs are involved. For example:

• Han sagde, at han ikke kom
  = He said that he was not coming

Notice how ikke comes before the verb in the subordinate clause.

Their dictionary forms are:

• gik → gå = to go
• begyndte → begynde = to begin

In this sentence they are both in the past tense:

• gå → gik
• begynde → begyndte

So:

• paraplyen går i stykker = the umbrella breaks / is breaking
• paraplyen gik i stykker = the umbrella broke

and

• regnen begynder = the rain starts
• regnen begyndte = the rain started

Yes, it is completely natural.

It sounds like normal spoken or written Danish:

• Det var uheldigt is a very common reaction
• min paraply gik i stykker is a very natural way to say an umbrella broke
• lige før regnen begyndte also sounds normal

A slightly more conversational version could be:

• Det var uheldigt, at min paraply gik i stykker lige før det begyndte at regne.

But your original sentence is already good, correct, and idiomatic.